1. Field of the Invention
The invention relates to a method of a testing 1394 interface card, and more particularly to a method of testing multi-port 1394 interface card.
2. Description of the Related Art
Due to the rapid development in computer industry, the corresponding peripheral equipments also have been greatly advanced. While the datum are transmitted between the computer and peripheral equipments, such as a printer, a scanner, a display, a keyboard, or another computer, a hardware interface must be installed for data transfer by defining physical interconnection characteristics and signal characteristics. Generally speaking, the serial transfer, such as RS-232, and parallel transfer are commonly used in the traditional method. However, both of them have the disadvantages of low transmitting speed and inconvenient connection.
Accordingly, the interface card of IEEE-1394, comprising the characteristics of hot-plug and high transmitting speed, is produced to satisfy the requirement of high quality in E era. Nowadays, the interface card of 1394 is more and more popular and provides advanced functions, for instance, a 1394 interface card of multi-port. After the manufacturing of a 1394 interface card is completed, a testing step is processed to insure the correctness of its function.
Referring to FIG. 1, it is a diagram for testing a 1394 interface card according to a traditional method. A 1394 interface card 102 to be tested comprises multiple ports, for instance, three ports of a zeroth port, a first port, and a second port. Three reference 1394 interface cards 104, 106, and 108, wherein each reference 1394 interface card is a 1394 interface card having already passed testing and verification, are provided, and each of them comprises a zeroth port, a first port, and a second port, respectively.
The three ports of 1394 interface card 102 to be tested are tested simultaneously and are respectively connected to the reference 1394 interface card 104, 106, 108 at the same time, wherein the zeroth port of the 1394 interface card 102 to be tested is connected to the zeroth port of the reference 1394 interface card 104 through cable 110, the first port of the 1394 interface card 102 to be tested is connected to the first port of the reference 1394 interface card 106 through cable 112, and the second port of the 1394 interface card to be tested 102 is connected to the second port of the reference 1394 interface card 108 through cable 114. However, using three reference 1394 interface cards at the same time increases the cost of testing.
For example, as the number of ports for the 1394 interface card to be tested 102 increases to six, the number of reference 1394 interface cards also increases to six. Accordingly, the number the peripheral component interconnect (PCI) slot is increased, too. However, the number of PCI slots on a main board develops in the trend of decreasing for the reason that the chips are highly integrated. Therefore, the number of main boards used in the process of testing should be increased, which causes the increasing of the testing complexity and the probability of testing error.
Referring to FIG. 2, it is a diagram for testing a 1394 card by simply using a reference 1394 interface card, wherein two ports of 1394 interface card 102 to be tested are connected to the two ports of the reference 1394 interface card 204. In this example, the connections between the 1394 interface card 102 to be tested and the reference 1394 interface card do not obey the rule of tree structure and a closed loop is formed to cause the abnormal operations for the 1394 interface card 102 to be tested and the reference 1394 interface card.
In still another traditional method, the three ports of 1394 interface card 102 to be tested are tested sequentially by using one reference 1394 interface card at a time to avoid the closed loop problem, wherein one port of the 1394 interface card 102 to be tested is connected to one port of the reference 1394 interface card. However, the actions of connection and disconnection between ports and cables increase the probability of testing error.